test: use `ModuleNotFoundError` in `interface_ipc.py` #34409

pull fanquake wants to merge 1 commits into bitcoin:master from fanquake:use_module_not_found changing 1 files +1 −1

fanquake commented at 11:58 AM on January 26, 2026: member

Change this so we catch the case where the capnp shared libs have been updated, and can no-longer be loaded by the Python module, resulting in a skipped test, even though pycapnp is installed. i.e:

stderr:
Traceback (most recent call last):
  File "/root/ci_scratch/build/test/functional/interface_ipc.py", line 20, in <module>
    import capnp  # type: ignore[import] # noqa: F401
    ^^^^^^^^^^^^
  File "/usr/local/lib64/python3.14/site-packages/capnp/__init__.py", line 36, in <module>
    from .version import version as __version__
  File "/usr/local/lib64/python3.14/site-packages/capnp/version.py", line 1, in <module>
    from .lib.capnp import _CAPNP_VERSION_MAJOR as LIBCAPNP_VERSION_MAJOR  # noqa: F401
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
ImportError: libcapnpc.so.1.0.1: cannot open shared object file: No such file or directory

Failing in this way should make it clear that pycapnp needs to be reinstalled/rebuilt.

If pycapnp is not installed, the test still skips as expected:

Remaining jobs: [interface_ipc.py]
1/1 - interface_ipc.py skipped (capnp module not available.)

TEST             | STATUS    | DURATION

interface_ipc.py | ○ Skipped | 0 s

Fixes: #34016.

test: use ModuleNotFoundError in interface_ipc.py

Change this so we catch the case where the capnp shared libs have been
updated, and can no-longer be loaded by the Python module, resulting in
a skipped test, even though pycapnp is installed. i.e:
```bash
stderr:
Traceback (most recent call last):
  File "/root/ci_scratch/build/test/functional/interface_ipc.py", line 20, in <module>
    import capnp  # type: ignore[import] # noqa: F401
    ^^^^^^^^^^^^
  File "/usr/local/lib64/python3.14/site-packages/capnp/__init__.py", line 36, in <module>
    from .version import version as __version__
  File "/usr/local/lib64/python3.14/site-packages/capnp/version.py", line 1, in <module>
    from .lib.capnp import _CAPNP_VERSION_MAJOR as LIBCAPNP_VERSION_MAJOR  # noqa: F401
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
ImportError: libcapnpc.so.1.0.1: cannot open shared object file: No such file or directory
```

Failing in this way should make it clear that `pycapnp` needs to be
reinstalled/rebuilt.

If  `pycapnp` is not installed, the test still skips as expected:
```bash
Remaining jobs: [interface_ipc.py]
1/1 - interface_ipc.py skipped (capnp module not available.)

TEST             | STATUS    | DURATION

interface_ipc.py | ○ Skipped | 0 s
```

Fixes: #34016.

Co-authored-by: Ryan Ofsky <ryan@ofsky.org>

905dfdee86

DrahtBot added the label Tests on Jan 26, 2026
DrahtBot commented at 11:58 AM on January 26, 2026: contributor



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For details see: https://corecheck.dev/bitcoin/bitcoin/pulls/34409.



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ACK maflcko, hebasto, sedited

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maflcko commented at 1:04 PM on January 26, 2026: member

lgtm ACK 905dfdee86d679f8ea31d841bceb77a5724a6b1b

I have not tested this.
hebasto approved
hebasto commented at 1:14 PM on January 26, 2026: member

ACK 905dfdee86d679f8ea31d841bceb77a5724a6b1b, I have reviewed the code and it looks OK. However, I'm not able to reproduce #34016.
sedited approved
sedited commented at 2:44 PM on January 28, 2026: contributor

ACK 905dfdee86d679f8ea31d841bceb77a5724a6b1b
sedited merged this on Jan 28, 2026
sedited closed this on Jan 28, 2026
fanquake deleted the branch on Jan 29, 2026

Type	Reviewers
ACK	maflcko, hebasto, sedited

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#34016 test: `interface_ipc.py` might start skipping if installed capnp version changes #34459 [30.x] Backports

test: use `ModuleNotFoundError` in `interface_ipc.py` #34409

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